Sunflower is generally cultivated for obtaining oil which has saturated fatty acids (palmitic and stearic) and unsaturated fatty acids (oleic and linoleic), the stearic acid content is always less than 10% (Gunstone, F. D. et al. “The lipid handbook”; Chapman and Hall 1986), normally comprised between 3% and 7. In relation with the unsaturated fatty acids there are two different kinds of sunflower seeds: the normal sunflower which has a linoleic acid content between 50% and 70% (Knowles, P. F.
“Recent advances in oil crops breeding”; ROCS Proceedings 1988) and the high oleic sunflower which has 2-10% of linoleic acid and 75-90% of oleic acid (Soldatov, K.l. “Chemical mutagenesis in sunflower breeding ”; Int. Proc. 7th Intern. Sunflower Conference, 352-357, 1976). Another high oleic sunflower line has been referred by Fick (US-B1-4627192), with oleic acid content of approximately 80 %
Referring to saturated fatty acids, high stearic sunflower lines are disclosed in WO 95/20313.
Further references to sunflower lines with high palmitic acid content are WO 96/39804 and Retske et al. “Triacylglycerol composition and structure in genetically modified sunflower and soybean oils”; JAOCS 74, 989-998 (1997), European Patent Appl. 98201871.5 and Nikolova et al. “Gametocidal effect of gibberellic acid (GA3) on biochemical characteristics of sunflower seeds” Helia, 15, Nr. 17, 45-50, (1992). In all these lines, the increase in palmitic acid implies higher palmitoleic acid content, always over 4%, and where the two “cis” isomers n-7 octadecenoic acid (asclepic) and n-9 octadecenoic (oleic) acid have been analyzed, an increase in the n-7 (asclepic acid) isomer has been observed.
Table 1 shows the fatty acid composition for all this indicated sunflower oil varieties.
TABLE 1Fatty acids composition (%)ReferenceLine16:016:116:218:018:118:1A18:220:022:0GunstoneNormal6——518—68—1Oleic5——488—2—1Nikolova, 1992295*29*55**Reske, 1997256*360*4—2274*317*47—1CAS-5315135647—1CAS-12307—25243—2* These fatty acids were not determined in those papers. — = Traces. 
The saturated fatty acid content of an oil is directly related with the physical and chemical characteristics thereof. In case that said content is sufficiently high, the oil can be a solid at room temperature like some animal fats. Normal sunflower oil is always a liquid under said conditions. In the food industry like for the production of confectionery or margarine; animal fats or hydrogenated vegetable fats are usually used because a solid or semisolid product is required. By means of hydrogenation unsaturated fatty acids are converted into saturated fatty acids. Animal fats as well as hydrogenated fats are not very recommendable from a nutritional point of view (Chow, C. K. “Fatty acids in food and their health implications”, Dekker, N.Y. , 1992). Animal fats have a relatively high cholesterol content. Too much cholesterol in the diet may be detrimental to the health. Therefore animal fats have been substituted in the last years by hydrogenated vegetable fats which do not contain cholesterol.
However, said hydrogenated fats present another problem derived from the hydrogenation process. In said process positional isomerization (shift or double bonds) and stereo-chemical transformations (formation of “trans” isomers) take place. Isomers are produced in an amount of up to 30%-50% of the total fatty acids amount. These isomers are not very healthy from a nutritional point of view (Wood, R. “Biological effects of geometrical and positional isomers of monounsaturated fatty acids in humans”, Dekker, N.Y. 1990; Willet, W. C. & Ascherio, A. , “Trams Fatty Acids: Are the effects only marginal?”, American Journal of Public Health, Vol. 84,5, 1994). Therefore, the use of hydrogenated fats in the food industry should be avoided.
As previously referred, the increase in palmitic acid implies higher palmitoleic acid contents, always over 4% (see WO 96/39804). These oils are useful for food industry which requires high thermostability, but the presence of the indicated palmitoleic acid contents is still undesirable. Studies carried out on macadamia oil, which has 4% palmitoleic acid content indicate a negative effect on plasmatic cholesterol when compared with palmitic and oleic (Nestel et al., “Effects of increasing dietary palmitoleic acid compared with palmitic and oleic acids on plasma lipids of hypercholesterolemic men”, Journal Lipid Research, vol. 35, pp. 656-662, 1994). This oil has also higher asclepic acid contents (n-7 isomer of octadecanoic acid) than other normal sunflower oil that have 0.6 % or other vegetable oils, like soybean or rape which have 0.8 and 0.9 % respectively (Mukherjee K. D. and Kiewitt I., “Formation of (n-9) and (n-7) cis-monounsaturated fatty acids in seeds of higher plants”, Planta, vol. 149, pp. 461-463.
It can be concluded that an oil having higher palmitic and stearic acid contents than normal sunflower oil, but maintaining reduced levels of palmitoleic and asclepic acids would meet all the requirements for food industry implying high thermostability and plasticity to be spread.